19 replies to this topic

[bluemini1979]

Hi
Is it 8mm fuel line I need. I'm using a gt17 turbo and metro turbo hif44. I no I need to run 2 so I have a return

[Ethel]

I reckon the Metty had 8mm lines because that's what the pressure regulator and pump had. I think 1/4" (6mm) would suffice, it'll depend on your pump's pressure and how much juice the engine needs (target BHP).

[bluemini1979]

Target is 130hp. I haven't bought a pump yet but painting the floors on Monday and putting rear frame in Tuesday so need fuel lines in before subframes

[coopdog]

8mm for both :)

[HUBBA.HUBBA]

I would go for 10mm and a 8mm return. You don't want performance compromised for the sake of spenfing a couple of quid more, and it would future proof things if you want to go for higher power in the future. The standard spi fuel line is 10mm.imo

[59 Speed]

The standard spi fuel line is 10mm.imo

10mm? Inner diameter? Are you sure?

[HUBBA.HUBBA]

The standard spi fuel line is 10mm.imo

10mm? Inner diameter? Are you sure?

No, outer diameter. Of course any hoses off the fixed fuel line would be 10mm inner.

Edited by HUBBA.HUBBA, 13 December 2015 - 07:22 PM.

[bluemini1979]

Why feed with a bigger pipe? Surely if 10mm of fuel can get there 10mm of fuel would need to come away. I work on hydraulics and they always have a larger return

[kezzkitkat]

to be honest people have ran 6mm on both or 8mm on both or the common 8/10mm return 

i personal run 8mm on both and have no trouble 

you will need around 4 meter each way 

[bluemini1979]

Ok thanks my dads a plumber and has a new roll of 8mm on his van so I'll nick a bit of that ;)

[HUBBA.HUBBA]

Why feed with a bigger pipe? Surely if 10mm of fuel can get there 10mm of fuel would need to come away. I work on hydraulics and they always have a larger return

Less fuel is being returned to the fuel tank than leaving the fuel tank as some of the fuel will be used to run the thing at the front of your car called an engine. There will be less flow and less pressure on the return. All it's doing is returning unused fuel back to the tank via the regulator.
Out of interest aren't hydraulics returns pumped?

Edited by HUBBA.HUBBA, 14 December 2015 - 08:13 AM.

[Turbo Nick]

8mm feed, 10mm return.

 

Get any kind of restriction in your return and you'll have fuel pressure issues.

[Ethel]

That makes sense as the regulator will be held open if the pressure can't leak away fast enough. Though bigger lines hold more fuel for inertia to act on. 6mm ought to flow plenty of juice for most though. Feeding the return back in just before the pump inlet should held flow in both directions, especially if you have a carb Mini tank with a 6mm outlet.

[mad mk1]

I find 8mm both ways works fine with 200+ Bhp

so it's up to you

[burchy35]

8mm feed, 10mm return.  no problem with 180bhp i run.